DESCRIPTION: This study will assess the impact of receiving ambulatory care from primary care physicians and/or cardiologists after an acute myocardial infarction (AMI) for Medicare beneficiaries in California, Florida, Massachusetts, New York, Ohio, Pennsylvania and Texas. Prior studies have yielded valuable insights about the quality of in-hospital AMI care, but analyses of ambulatory care for post-MI patients have been much more limited. The proposed study will have three specific aims: 1) To assess access to cardiologists for post-MI ambulatory care; 2) To assess the association of physician speciality (and type of insurance) with the use of effective cardiac therapies in ambulatory care; and 3) To assess the impact of physician speciality on long-term post-MI outcomes, including mortality, cardiac symptoms, and functional status. Using extensive clinical and claims data, access to speciality care and 18-month mortality will be analyzed for approximately 49,000 AMI patients discharged during 1994 and 1995 and subsequently treated solely or collaboratively by primary care physicians and cardiologists. Use of cardiac drugs and health-related quality of life will be evaluated for a random sub-sample of approximately 3,600 fee-for-service and HMO patients who have completed a detailed survey 18 months after discharge. Particular attention will be devoted to comparing the effects of collaborative primary and speciality care with primary or specialty care alone. Advanced statistical methods, including propensity-score analyses and hierarchical modeling, will be used to analyze the consequences of collaborative care and speciality care more accurately. The results of this study will help guide efforts to improve quality of care and enhance collaboration among different types of physicians caring for post-MI patients within medical groups and systems of managed care. REVIEW 1